Systems and methods for medical instrument compression compensation

ABSTRACT

Certain aspects relate to systems and techniques for compensating for compression in elongated shafts of medical instruments. Medical instruments can include elongated shafts that may experience compression when articulated. The medical instruments can be attached to instrument positioning devices that are configured to move the medical instruments to compensate for this compression. For example, an instrument positioning device can advance a medical instrument to compensate for compression in an elongated shaft of the medical instrument. In some instances, the amount of compression is determined using a compression compensation parameter. The compression compensation parameter can be determined during a calibration process of the medical instrument.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a divisional of application Ser. No. 15/640,277,filed Jun. 30, 2017, which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The systems and methods disclosed herein are directed to medicalinstruments, and more particularly to systems and methods thatcompensate for compression of elongated shafts of the medicalinstruments.

BACKGROUND

Medical procedures may involve accessing and visualizing an internalregion of a patient for diagnostic or therapeutic purposes. Endoscopy,for example, may include accessing and visualizing the inside of apatient's lumen (e.g., airways). As another example, laparoscopy mayinclude accessing and visualizing an internal cavity of a patient.During a procedure, a medical instrument such as, for example, a scope,may be inserted into the patient's body and an instrument can be passedthrough the scope to a tissue site identified for diagnosis and/ortreatment.

In some instances, the medical instrument can include an elongated shaft(or an elongated body generally) that is steerable or articulable so asto navigate an interior region of the patient. In some instances, themedical instrument can be robotically controlled.

SUMMARY

The systems, techniques and devices of this disclosure each have severalinnovative aspects, no single one of which is solely responsible for thedesirable attributes disclosed herein.

In some instances, medical instruments include elongated shaftsconfigured for insertion into a body of a patient. The elongated shaftscan be articulable so that they can be navigated within the patient. Theelongated shafts can include pull wires that are actuable to articulatethe elongated shafts. Pull wire-based movements (i.e., movements causedby actuating the pull wires) may cause undesirable compression (e.g.,axial compression) of the elongated shafts. The systems and methods ofthe present disclosure can compensate for this compression bydetermining the amount of the compression and moving (e.g., advancing)the medical instrument with an instrument positioning device (e.g., arobotic arm) to compensate for the compression.

In some instances, a compression compensation parameter is used todetermine the compression of the elongated shaft of the medicalinstrument. The compression compensation parameter can relate acharacteristic of pull wire-based movement (e.g., pull wire tension,pull wire displacement, actuator displacement, commanded angle ofarticulation, measured angle of articulation, etc.) to axialcompression. The compression compensation parameter can be determinedduring a calibration process of the medical instrument. The compressioncompensation parameter can be stored in a memory (e.g., non-transitorycomputer readable medium) on the medical instrument.

Accordingly, a first aspect of the disclosure relates to a medicalinstrument. The medical instrument includes an elongated shaft extendingbetween a distal portion and a proximal portion. The elongated shaft isconfigured for insertion, in use, into a lumen of a patient. The medicalinstrument also includes an instrument base connected to the proximalportion of the elongated shaft. The instrument base includes anattachment interface configured to facilitate attachment to a roboticarm. The medical instrument also includes a non-transitory computerreadable medium storing a compression compensation parameter thatrelates movement of the elongated shaft to axial compression of theelongated shaft. The medical instrument also includes a pull wireconnected to the distal portion of the elongated shaft. The pull wireextends along the elongated shaft between the distal portion and a driveinput positioned at the instrument base. The drive input configured toactuate the pull wire to cause movement of the elongated shaft based atleast in part on the stored compression compensation parameter.

The medical instrument of the first aspect may include one or more ofthe following features, in any combination: (a) movement of theelongated shaft comprises articulation of the elongated shaft, and thecompression compensation parameter relates an angle of articulation ofthe elongated shaft to an axial length of compression of the elongatedshaft; (b) the angle of articulation comprises a commanded angle ofarticulation; (c) the angle of articulation comprises a measured angleof articulation; (d) at least one electromagnetic (EM) sensor ispositioned on the elongated shaft, and the measured angle ofarticulation is determined based on a signal from the EM sensor; (e) ashape-sensing fiber is included on the elongated shaft, and the measuredangle of articulation is determined based on the shape-sensing fiber;(f) at least one tension sensor is connected to the pull wire; (g) thecompression compensation parameter relates a tension in the pull wire,as measured by the tension sensor, to an axial length of compression ofthe elongated shaft; (h) the compression compensation parameter relatesa pull wire displacement to an axial length of compression of theelongated shaft; (i) the drive input comprises a pulley, and thecompression compensation parameter relates a rotation of the pulley toan axial length of compression of the elongated shaft; (j) the driveinput comprises at least one of a lever, a trigger, a crank, and a cam;(k) the drive input comprises a linear drive input, and the compressioncompensation parameter relates a linear displacement of a portion of thelinear drive input to an axial length of compression of the elongatedshaft; (l) the compression compensation parameter is determined during acalibration process of the medical instrument; (m) the non-transitorycomputer readable medium comprises a radio frequency identification(RFID) tag; (n) the RFID tag is positioned at the instrument base; (o)the RFID tag is configured to communicate the compression compensationparameter when activated by a RFID reader of the robotic arm; (p) theelongated shaft comprises an endoscope; (q) the elongated shaftcomprises a sheath having a channel formed therethrough, the channelextending along an axis of the sheath; and/or (r) one or more additionalpull wires.

In a second aspect, the disclosure relates to a robotic system. Therobotic system includes a first medical instrument configured forinsertion, in use, into a lumen of a patient. The first instrumentincludes: a first elongated shaft, a first pull wire actuable to causepull wire-based movement of the first elongated shaft, and a firstinstrument base including a first drive input for actuating the firstpull wire. The system includes a first instrument positioning deviceattached to the first instrument base and configured to move to advanceor retract the first instrument through the lumen of the patient. Thesystem includes at least one non-transitory computer readable mediumhaving stored thereon executable instructions. The system also includesat least one processor in communication with the at least onenon-transitory computer readable medium and configured to execute theinstructions to cause the system to at least: determine an axialcompression of the first elongated shaft; and move the first instrumentpositioning device to either advance or retract the first elongatedshaft of the first instrument through the lumen of the patient tocompensate for the determined axial compression of the first elongatedshaft.

The robotic system of the second aspect may include one or more of thefollowing features, in any combination: (a) the instructions cause theat least one processor to determine the axial compression of the firstelongated shaft using a compression compensation parameter that relatespull wire-based movement of the first elongated shaft to axialcompression of the first elongated shaft; (b) the pull wire-basedmovement causes articulation of the elongated shaft, and the compressioncompensation parameter relates an angle of articulation of the elongatedshaft to an axial length of compression of the elongated shaft; (c) theangle of articulation comprises a commanded angle of articulation; (d)the angle of articulation comprises a measured angle of articulation;(e) at least one EM sensor positioned on the first elongated shaft,wherein the measured angle of articulation is determined based on asignal from the EM sensor; (f) a shape-sensing fiber on the firstelongated shaft, and wherein the measured angle of articulation isdetermined based on the shape-sensing fiber; (g) the compressioncompensation parameter is determined during a calibration process of thefirst medical instrument; (h) an RFID tag on the first medicalinstrument, the RFID tag storing the compression compensation parameter,and an RFID reader connected to the at least one processor; (i) the RFIDtag is positioned on the first instrument base, and the RFID reader ispositioned on the first instrument positioning device; (j) the firstmedical instrument comprises an endoscope; (k) the first medicalinstrument comprises a sheath; (l) a second medical instrumentconfigured for insertion through a working channel of the firstinstrument into the lumen of the patient, the second instrumentcomprising a second elongated shaft, a second pull wire actuable toarticulate the second elongated shaft, and a second instrument baseincluding a second drive input for actuating the second pull wire, asecond instrument positioning device attached to the second instrumentand configured to move to advance or retract the second instrumentthrough the working channel of the first instrument, and wherein theinstructions cause the at least one processor to move the secondinstrument positioning device to either advance or retract the secondelongated shaft of the second medical instrument through the workingchannel of the first instrument; (m) the instructions cause the at leastone processor to determine an axial compression of the second elongatedshaft, and move the second instrument positioning device to eitheradvance or retract the second elongated shaft of the second medicalinstrument through the working channel of the first medical instrumentto compensate for the determined axial compression of the secondelongated shaft; (n) the instructions cause the at least one processorto move the second instrument positioning device to either advance orretract the second elongated shaft of the second instrument through theworking channel of the first medical instrument to compensate for thedetermined axial compression of the first elongated shaft; and/or (o)the first instrument comprises a sheath and the second instrumentcomprises an endoscope.

In a third aspect of the disclosure a robotic system includes a firstmedical instrument configured for insertion, in use, into a lumen of apatient. The first instrument includes a first elongated shaft, a firstpull wire actuable to articulate the first elongated shaft, and a firstinstrument base including a first drive input for actuating the firstpull wire. A first instrument positioning device is attached to thefirst instrument base and configured to move to advance or retract thefirst medical instrument through the lumen of the patient. The roboticsystem includes a second instrument configured for insertion through aworking channel of the first medical instrument into the lumen of thepatient. The second medical instrument includes a second elongatedshaft, a second pull wire actuable to articulate the second elongatedshaft, and a second instrument base including a second drive input foractuating the second pull wire. A second instrument positioning deviceis attached to the second instrument base and configured to move toadvance or retract the second instrument through the working channel ofthe first instrument. The system also includes at least onenon-transitory computer readable medium having stored thereon executableinstructions, and at least one processor in communication with the atleast one non-transitory computer readable medium and configured toexecute the instructions to cause the system to at least: determine anaxial compression of the first elongated shaft; move the firstinstrument positioning device to advance the first elongated shaft ofthe first medical instrument through the lumen of the patient tocompensate for a first portion of the determined axial compression ofthe first elongated shaft; and move the second instrument positioningdevice to advance the second elongated shaft of the second medicalinstrument through the working channel of the first instrument tocompensate for a second portion of the determined axial compression ofthe first elongated shaft. The second portion may be larger than thefirst portion.

In a fourth aspect, a robotic system includes a first medical instrumentconfigured for insertion, in use, into a lumen of a patient. The firstinstrument includes a first elongated shaft, a first pull wire actuableto articulate the first elongated shaft, and a first instrument baseincluding a first drive input for actuating the first pull wire. A firstinstrument positioning device is attached to the first instrument baseand configured to move to advance or retract the first medicalinstrument through the lumen of the patient. The system also includes asecond instrument configured for insertion through a working channel ofthe first medical instrument into the lumen of the patient. The secondmedical instrument includes a second elongated shaft, a second pull wireactuable to articulate the second elongated shaft, and a secondinstrument base including a second drive input for actuating the secondpull wire. A second instrument positioning device is attached to thesecond instrument base and configured to move to advance or retract thesecond instrument through the working channel of the first instrument.The system also includes at least one non-transitory computer readablemedium having stored thereon executable instructions, and at least oneprocessor in communication with the at least one non-transitory computerreadable medium and configured to execute the instructions to cause thesystem to at least: determine an axial compression of the secondelongated shaft; move the first instrument positioning device to advancethe first elongated shaft of the first medical instrument through thelumen of the patient to compensate for a first portion of the determinedaxial compression of the second elongated shaft; and move the secondinstrument positioning device to advance the second elongated shaft ofthe second medical instrument through the working channel of the firstinstrument to compensate for a second portion of the determined axialcompression of the second elongated shaft. The second portion may belarger than the first portion.

In a fifth aspect of the disclosure, a non-transitory computer readablestorage medium has stored thereon instructions that, when executed,cause a processor of a device to at least: determine, based at least inpart on information indicative of a pull wire-based movement of anelongated shaft of a first medical instrument and a compressioncompensation parameter, an axial compression of the first elongatedshaft of the first instrument; and move a first instrument positioningdevice connected to the first medical instrument to compensate for theaxial compression of the first elongated shaft.

The non-transitory computer readable storage medium of the fifth aspectmay include one or more of the following features, in any combination:(a) the information indicative of the pull-wire based movement comprisesinformation indicative of a commanded articulation for the first medicalinstrument; (b) the information indicative of the pull-wire basedmovement comprises information indicative of a measured articulation forthe first medical instrument; (c) the compression compensation parameteris determined during a calibration process of the first medicalinstrument; (d) the compression compensation parameter relates an angleof articulation of the first elongated shaft to an axial length ofcompression of the first elongated shaft; (e) the compressioncompensation parameter relates a tension in a pull wire of the firstinstrument to an axial length of compression of the first elongatedshaft; (f) the compression compensation parameter relates a displacementof a pull wire of the first instrument to an axial length of compressionof the first elongated shaft; (g) the compression compensation parameterrelates a rotation of a pulley attached to a pull wire of the firstinstrument to an axial length of compression of the first elongatedshaft; and/or (h) the instructions, when executed, cause the processorto move the first instrument positioning device to advance the elongatedshaft of the first articulable medical instrument into a lumen of apatient.

In a sixth aspect of the disclosure, a method for calibrating a medicalinstrument comprising an articulable elongated shaft, includes:determining a pull wire-based movement for moving the elongated shaft toa first position; determining, with the elongated shaft in the firstposition, an axial compression of the elongated shaft; and determining,by relating the first position to the determined axial compression, acompression compensation parameter for the elongated shaft.

The method of the sixth aspect may also include one or more of thefollowing features, in any combination: (a) articulating the elongatedshaft to the first position; (b) articulating the elongated shaftcomprises tensioning a pull wire connected to a distal portion of theelongated shaft; (c) wherein determining the pull wire-based movementcomprises measuring a tension in the pull wire; (d) attaching one ormore spatial caps to a distal portion of the elongated shaft, the one ormore spatial caps configured to provide spatial data about the locationand orientation of the distal portion of the elongated shaft, andwherein determining the pull wire-based movement comprises analyzing thespatial data; (e) wherein determining the axial compression comprisesanalyzing the spatial data; (f) wherein the elongated shaft comprises aspatial sensor configured to provide spatial data about the location andorientation of the distal portion of the elongated shaft, and whereindetermining the pull wire-based movement comprises analyzing the spatialdata; (g) wherein determining the axial compression comprises analyzingthe spatial data; (h) wherein the one or more spatial caps comprise oneor more EM sensors; (i) wherein determining the axial compressioncomprises measuring a length of the elongated shaft; (j) whereindetermining the articulation comprises measuring an angle of theelongated shaft; and/or (k) storing the compression compensationparameter in a non-transitory computer readable medium of the firstmedical instrument.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction withthe appended drawings, provided to illustrate and not to limit thedisclosed aspects, wherein like designations denote like elements.

FIG. 1 illustrates an embodiment of a cart-based robotic system arrangedfor diagnostic and/or therapeutic bronchoscopy.

FIG. 2 depicts further aspects of the robotic system of FIG. 1 .

FIG. 3 illustrates an embodiment of the robotic system of FIG. 1arranged for ureteroscopy.

FIG. 4 illustrates an embodiment of the robotic system of FIG. 1arranged for a vascular procedure.

FIG. 5 illustrates an embodiment of a table-based robotic systemarranged for a bronchoscopic procedure.

FIG. 6 provides an alternative view of the robotic system of FIG. 5 .

FIG. 7 illustrates an example system configured to stow robotic arm(s).

FIG. 8 illustrates an embodiment of a table-based robotic systemconfigured for an ureteroscopic procedure.

FIG. 9 illustrates an embodiment of a table-based robotic systemconfigured for a laparoscopic procedure.

FIG. 10 illustrates an embodiment of the table-based robotic system ofFIGS. 5-9 with pitch or tilt adjustment.

FIG. 11 provides a detailed illustration of the interface between thetable and the column of the table-based robotic system of FIGS. 5-10 .

FIG. 12 illustrates an exemplary instrument driver.

FIG. 13 illustrates an exemplary medical instrument with a pairedinstrument driver.

FIG. 14 illustrates an alternative design for an instrument driver andinstrument where the axes of the drive units are parallel to the axis ofthe elongated shaft of the instrument.

FIG. 15 depicts a block diagram illustrating a localization system thatestimates a location of one or more elements of the robotic systems ofFIGS. 1-10 , such as the location of the instrument of FIGS. 13-14 , inaccordance to an example embodiment.

FIG. 16A illustrates an embodiment of an elongated shaft of a medicalinstrument.

FIG. 16B depicts the elongated shaft of the medical instrument of FIG.16A experiencing axial compression caused by an example of pullwire-based movement.

FIG. 16C depicts the elongated shaft of the medical instrument of FIG.16A experiencing axial compression caused by another example ofpull-wire based movement.

FIG. 17A illustrates the medical instrument of FIG. 16A coupled to anembodiment of an instrument positioning device.

FIG. 17B depicts an example of the instrument positioning device of FIG.17A moving to compensate for axial compression caused by pull wire-basedmovement of the medical instrument.

FIG. 17C depicts an example of the instrument positioning device of FIG.17A moving to compensate for axial compression caused by pull wire-basedmovement of the medical instrument.

FIG. 18 is a flow chart illustrating an example method for compensatingfor compression in a medical instrument.

FIG. 19A illustrates an example of a second medical instrumenttelescoping within a working channel of a first medical instrument.

FIG. 19B depicts an example of axial compression of the first and secondmedical instruments caused by pull wire-based movement.

FIG. 19C illustrates that the axial compression of FIG. 19B can becompensated for by moving first and/or second instrument positioningdevices coupled to the first and second medical instruments,respectively.

FIG. 20 illustrates an embodiment of a medical instrument configured tocompensate for axial compression.

FIG. 21 depicts a block diagram of an embodiment of a system configuredto compensate for axial compression of medical instruments.

FIG. 22 is a flow chart illustrating an example method for calibrating amedical instrument.

DETAILED DESCRIPTION 1. Overview

Aspects of the present disclosure may be integrated into arobotically-enabled medical system capable of performing a variety ofmedical procedures, including both minimally invasive, such aslaparoscopy, and non-invasive, such as endoscopy, procedures. Amongendoscopic procedures, the system may be capable of performingbronchoscopy, ureteroscopy, gastroscopy, etc.

In addition to performing the breadth of procedures, the system mayprovide additional benefits, such as enhanced imaging and guidance toassist the physician. Additionally, the system may provide the physicianwith the ability to perform the procedure from an ergonomic positionwithout the need for awkward arm motions and positions. Still further,the system may provide the physician with the ability to perform theprocedure with improved ease of use such that one or more of theinstruments of the system can be controlled by a single user.

Various embodiments will be described below in conjunction with thedrawings for purposes of illustration. It should be appreciated thatmany other implementations of the disclosed concepts are possible, andvarious advantages can be achieved with the disclosed implementations.Headings are included herein for reference and to aid in locatingvarious sections. These headings are not intended to limit the scope ofthe concepts described with respect thereto. Such concepts may haveapplicability throughout the entire specification.

A. Robotic System-Cart

The robotically-enabled medical system may be configured in a variety ofways depending on the particular procedure. FIG. 1 illustrates anembodiment of a cart-based robotically-enabled system 10 arranged for adiagnostic and/or therapeutic bronchoscopy. During a bronchoscopy, thesystem 10 may comprise a cart 11 having one or more robotic arms 12 todeliver a medical instrument, such as a steerable endoscope 13, whichmay be a procedure-specific bronchoscope for bronchoscopy, to a naturalorifice access point (i.e., the mouth of the patient positioned on atable in the present example) to deliver diagnostic and/or therapeutictools. As shown, the cart 11 may be positioned proximate to thepatient's upper torso in order to provide access to the access point.Similarly, the robotic arms 12 may be actuated to position thebronchoscope relative to the access point. The arrangement in FIG. 1 mayalso be utilized when performing a gastro-intestinal (GI) procedure witha gastroscope, a specialized endoscope for GI procedures. FIG. 2 depictsan example embodiment of the cart in greater detail.

With continued reference to FIG. 1 , once the cart 11 is properlypositioned, the robotic arms 12 may insert the steerable endoscope 13into the patient robotically, manually, or a combination thereof. Asshown, the steerable endoscope 13 may comprise at least two telescopingparts, such as an inner leader portion and an outer sheath portion, eachportion coupled to a separate instrument driver from the set ofinstrument drivers 28, each instrument driver coupled to the distal endof an individual robotic arm. This linear arrangement of the instrumentdrivers 28, which facilitates coaxially aligning the leader portion withthe sheath portion, creates a “virtual rail” 29 that may be repositionedin space by manipulating the one or more robotic arms 12 into differentangles and/or positions. The virtual rails described herein are depictedin the Figures using dashed lines, and accordingly the dashed lines donot depict any physical structure of the system. Translation of theinstrument drivers 28 along the virtual rail 29 telescopes the innerleader portion relative to the outer sheath portion or advances orretracts the endoscope 13 from the patient. The angle of the virtualrail 29 may be adjusted, translated, and pivoted based on clinicalapplication or physician preference. For example, in bronchoscopy, theangle and position of the virtual rail 29 as shown represents acompromise between providing physician access to the endoscope 13 whileminimizing friction that results from bending the endoscope 13 into thepatient's mouth.

The endoscope 13 may be directed down the patient's trachea and lungsafter insertion using precise commands from the robotic system untilreaching the target destination or operative site. In order to enhancenavigation through the patient's lung network and/or reach the desiredtarget, the endoscope 13 may be manipulated to telescopically extend theinner leader portion from the outer sheath portion to obtain enhancedarticulation and greater bend radius. The use of separate instrumentdrivers 28 also allows the leader portion and sheath portion to bedriven independently of each other.

For example, the endoscope 13 may be directed to deliver a biopsy needleto a target, such as, for example, a lesion or nodule within the lungsof a patient. The needle may be deployed down a working channel thatruns the length of the endoscope to obtain a tissue sample to beanalyzed by a pathologist. Depending on the pathology results,additional tools may be deployed down the working channel of theendoscope for additional biopsies. After identifying a nodule to bemalignant, the endoscope 13 may endoscopically deliver tools to resectthe potentially cancerous tissue. In some instances, diagnostic andtherapeutic treatments may need to be delivered in separate procedures.In those circumstances, the endoscope 13 may also be used to deliver afiducial to “mark” the location of the target nodule as well. In otherinstances, diagnostic and therapeutic treatments may be delivered duringthe same procedure.

The system 10 may also include a movable tower 30, which may beconnected via support cables to the cart 11 to provide support forcontrols, electronics, fluidics, optics, sensors, and/or power to thecart 11. Placing such functionality in the tower 30 allows for a smallerform factor cart 11 that may be more easily adjusted and/orre-positioned by an operating physician and his/her staff. Additionally,the division of functionality between the cart/table and the supporttower 30 reduces operating room clutter and facilitates improvingclinical workflow. While the cart 11 may be positioned close to thepatient, the tower 30 may be stowed in a remote location to stay out ofthe way during a procedure.

In support of the robotic systems described above, the tower 30 mayinclude component(s) of a computer-based control system that storescomputer program instructions, for example, within a non-transitorycomputer-readable storage medium such as a persistent magnetic storagedrive, solid state drive, etc. The execution of those instructions,whether the execution occurs in the tower 30 or the cart 11, may controlthe entire system or sub-system(s) thereof. For example, when executedby a processor of the computer system, the instructions may cause thecomponents of the robotics system to actuate the relevant carriages andarm mounts, actuate the robotics arms, and control the medicalinstruments. For example, in response to receiving the control signal,the motors in the joints of the robotics arms may position the arms intoa certain posture.

The tower 30 may also include a pump, flow meter, valve control, and/orfluid access in order to provide controlled irrigation and aspirationcapabilities to system that may be deployed through the endoscope 13.These components may also be controlled using the computer system of thetower 30. In some embodiments, irrigation and aspiration capabilitiesmay be delivered directly to the endoscope 13 through separate cable(s).

The tower 30 may include a voltage and surge protector designed toprovide filtered and protected electrical power to the cart 11, therebyavoiding placement of a power transformer and other auxiliary powercomponents in the cart 11, resulting in a smaller, more moveable cart11.

The tower 30 may also include support equipment for the sensors deployedthroughout the robotic system 10. For example, the tower 30 may includeoptoelectronics equipment for detecting, receiving, and processing datareceived from the optical sensors or cameras throughout the roboticsystem 10. In combination with the control system, such optoelectronicsequipment may be used to generate real-time images for display in anynumber of consoles deployed throughout the system, including in thetower 30. Similarly, the tower 30 may also include an electronicsubsystem for receiving and processing signals received from deployedelectromagnetic (EM) sensors. The tower 30 may also be used to house andposition an EM field generator for detection by EM sensors in or on themedical instrument.

The tower 30 may also include a console 31 in addition to other consolesavailable in the rest of the system, e.g., console mounted on top of thecart. The console 31 may include a user interface and a display screen,such as a touchscreen, for the physician operator. Consoles in thesystem 10 are generally designed to provide both robotic controls aswell as preoperative and real-time information of the procedure, such asnavigational and localization information of the endoscope 13. When theconsole 31 is not the only console available to the physician, it may beused by a second operator, such as a nurse, to monitor the health orvitals of the patient and the operation of the system 10, as well as toprovide procedure-specific data, such as navigational and localizationinformation.

The tower 30 may be coupled to the cart 11 and endoscope 13 through oneor more cables or connections (not shown). In some embodiments, thesupport functionality from the tower 30 may be provided through a singlecable to the cart 11, simplifying and de-cluttering the operating room.In other embodiments, specific functionality may be coupled in separatecabling and connections. For example, while power may be providedthrough a single power cable to the cart 11, the support for controls,optics, fluidics, and/or navigation may be provided through a separatecable.

FIG. 2 provides a detailed illustration of an embodiment of the cart 11from the cart-based robotically-enabled system shown in FIG. 1 . Thecart 11 generally includes an elongated support structure 14 (oftenreferred to as a “column”), a cart base 15, and a console 16 at the topof the column 14. The column 14 may include one or more carriages, suchas a carriage 17 (alternatively “arm support”) for supporting thedeployment of one or more robotic arms 12 (three shown in FIG. 2 ). Thecarriage 17 may include individually configurable arm mounts that rotatealong a perpendicular axis to adjust the base of the robotic arms 12 forbetter positioning relative to the patient. The carriage 17 alsoincludes a carriage interface 19 that allows the carriage 17 tovertically translate along the column 14.

The carriage interface 19 is connected to the column 14 through slots,such as slot 20, that are positioned on opposite sides of the column 14to guide the vertical translation of the carriage 17. The slot 20contains a vertical translation interface to position and hold thecarriage 17 at various vertical heights relative to the cart base 15.Vertical translation of the carriage 17 allows the cart 11 to adjust thereach of the robotic arms 12 to meet a variety of table heights, patientsizes, and physician preferences. Similarly, the individuallyconfigurable arm mounts on the carriage 17 allow the robotic arm base 21of the robotic arms 12 to be angled in a variety of configurations.

In some embodiments, the slot 20 may be supplemented with slot coversthat are flush and parallel to the slot surface to prevent dirt andfluid ingress into the internal chambers of the column 14 and thevertical translation interface as the carriage 17 vertically translates.The slot covers may be deployed through pairs of spring spoolspositioned near the vertical top and bottom of the slot 20. The coversare coiled within the spools until deployed to extend and retract fromtheir coiled state as the carriage 17 vertically translates up and down.The spring-loading of the spools provides force to retract the coverinto a spool when the carriage 17 translates towards the spool, whilealso maintaining a tight seal when the carriage 17 translates away fromthe spool. The covers may be connected to the carriage 17 using, forexample, brackets in the carriage interface 19 to ensure properextension and retraction of the cover as the carriage 17 translates.

The column 14 may internally comprise mechanisms, such as gears andmotors, that are designed to use a vertically aligned lead screw totranslate the carriage 17 in a mechanized fashion in response to controlsignals generated in response to user inputs, e.g., inputs from theconsole 16.

The robotic arms 12 may generally comprise robotic arm bases 21 and endeffectors 22, separated by a series of linkages 23 that are connected bya series of joints 24, each joint comprising an independent actuator,each actuator comprising an independently controllable motor. Eachindependently controllable joint represents an independent degree offreedom available to the robotic arm 12. Each of the robotic arms 12 mayhave seven joints, and thus provide seven degrees of freedom. Amultitude of joints result in a multitude of degrees of freedom,allowing for “redundant” degrees of freedom. Having redundant degrees offreedom allows the robotic arms 12 to position their respective endeffectors 22 at a specific position, orientation, and trajectory inspace using different linkage positions and joint angles. This allowsfor the system to position and direct a medical instrument from adesired point in space while allowing the physician to move the armjoints into a clinically advantageous position away from the patient tocreate greater access, while avoiding arm collisions.

The cart base 15 balances the weight of the column 14, carriage 17, androbotic arms 12 over the floor. Accordingly, the cart base 15 housesheavier components, such as electronics, motors, power supply, as wellas components that either enable movement and/or immobilize the cart 11.For example, the cart base 15 includes rollable wheel-shaped casters 25that allow for the cart 11 to easily move around the room prior to aprocedure. After reaching the appropriate position, the casters 25 maybe immobilized using wheel locks to hold the cart 11 in place during theprocedure.

Positioned at the vertical end of the column 14, the console 16 allowsfor both a user interface for receiving user input and a display screen(or a dual-purpose device such as, for example, a touchscreen 26) toprovide the physician user with both preoperative and intraoperativedata. Potential preoperative data on the touchscreen 26 may includepreoperative plans, navigation and mapping data derived frompreoperative computerized tomography (CT) scans, and/or notes frompreoperative patient interviews. Intraoperative data on display mayinclude optical information provided from the tool, sensor andcoordinate information from sensors, as well as vital patientstatistics, such as respiration, heart rate, and/or pulse. The console16 may be positioned and tilted to allow a physician to access theconsole 16 from the side of the column 14 opposite the carriage 17. Fromthis position the physician may view the console 16, robotic arms 12,and patient while operating the console 16 from behind the cart 11. Asshown, the console 16 also includes a handle 27 to assist withmaneuvering and stabilizing the cart 11.

FIG. 3 illustrates an embodiment of a robotically-enabled system 10arranged for ureteroscopy. In a ureteroscopic procedure, the cart 11 maybe positioned to deliver a ureteroscope 32, a procedure-specificendoscope designed to traverse a patient's urethra and ureter, to thelower abdominal area of the patient. In a ureteroscopy, it may bedesirable for the ureteroscope 32 to be directly aligned with thepatient's urethra to reduce friction and forces on the sensitive anatomyin the area. As shown, the cart 11 may be aligned at the foot of thetable to allow the robotic arms 12 to position the ureteroscope 32 fordirect linear access to the patient's urethra. From the foot of thetable, the robotic arms 12 may insert the ureteroscope 32 along thevirtual rail 33 directly into the patient's lower abdomen through theurethra.

After insertion into the urethra, using similar control techniques as inbronchoscopy, the ureteroscope 32 may be navigated into the bladder,ureters, and/or kidneys for diagnostic and/or therapeutic applications.For example, the ureteroscope 32 may be directed into the ureter andkidneys to break up kidney stone build up using laser or ultrasoniclithotripsy device deployed down the working channel of the ureteroscope32. After lithotripsy is complete, the resulting stone fragments may beremoved using baskets deployed down the ureteroscope 32.

FIG. 4 illustrates an embodiment of a robotically-enabled system 10similarly arranged for a vascular procedure. In a vascular procedure,the system 10 may be configured such the cart 11 may deliver a medicalinstrument 34, such as a steerable catheter, to an access point in thefemoral artery in the patient's leg. The femoral artery presents both alarger diameter for navigation as well as relatively less circuitous andtortuous path to the patient's heart, which simplifies navigation. As ina ureteroscopic procedure, the cart 11 may be positioned towards thepatient's legs and lower abdomen to allow the robotic arms 12 to providea virtual rail 35 with direct linear access to the femoral artery accesspoint in the patient's thigh/hip region. After insertion into theartery, the medical instrument 34 may be directed and inserted bytranslating the instrument drivers 28. Alternatively, the cart may bepositioned around the patient's upper abdomen in order to reachalternative vascular access points, such as, for example, the carotidand brachial arteries near the shoulder and wrist.

B. Robotic System-Table

Embodiments of the robotically-enabled medical system may alsoincorporate the patient's table. Incorporation of the table reduces theamount of capital equipment within the operating room by removing thecart, which allows greater access to the patient. FIG. 5 illustrates anembodiment of such a robotically-enabled system arranged for abronchoscopic procedure. System 36 includes a support structure orcolumn 37 for supporting platform 38 (shown as a “table” or “bed”) overthe floor. Much like in the cart-based systems, the end effectors of therobotic arms 39 of the system 36 comprise instrument drivers 42 that aredesigned to manipulate an elongated medical instrument, such as abronchoscope 40 in FIG. 5 , through or along a virtual rail 41 formedfrom the linear alignment of the instrument drivers 42. In practice, aC-arm for providing fluoroscopic imaging may be positioned over thepatient's upper abdominal area by placing the emitter and detectoraround the table 38.

FIG. 6 provides an alternative view of the system 36 without the patientand medical instrument for discussion purposes. As shown, the column 37may include one or more carriages 43 shown as ring-shaped in the system36, from which the one or more robotic arms 39 may be based. Thecarriages 43 may translate along a vertical column interface 44 thatruns the length of the column 37 to provide different vantage pointsfrom which the robotic arms 39 may be positioned to reach the patient.The carriage(s) 43 may rotate around the column 37 using a mechanicalmotor positioned within the column 37 to allow the robotic arms 39 tohave access to multiples sides of the table 38, such as, for example,both sides of the patient. In embodiments with multiple carriages, thecarriages may be individually positioned on the column and may translateand/or rotate independently of the other carriages. While carriages 43need not surround the column 37 or even be circular, the ring-shape asshown facilitates rotation of the carriages 43 around the column 37while maintaining structural balance. Rotation and translation of thecarriages 43 allows the system 36 to align the medical instruments, suchas endoscopes and laparoscopes, into different access points on thepatient.

The robotic arms 39 may be mounted on the carriages 43 through a set ofarm mounts 45 comprising a series of joints that may individually rotateand/or telescopically extend to provide additional configurability tothe robotic arms 39. Additionally, the arm mounts 45 may be positionedon the carriages 43 such that, when the carriages 43 are appropriatelyrotated, the arm mounts 45 may be positioned on either the same side ofthe table 38 (as shown in FIG. 6 ), on opposite sides of the table 38(as shown in FIG. 9 ), or on adjacent sides of the table 38 (not shown).

The column 37 structurally provides support for the table 38, and a pathfor vertical translation of the carriages 43. Internally, the column 37may be equipped with lead screws for guiding vertical translation of thecarriages, and motors to mechanize the translation of said carriagesbased the lead screws. The column 37 may also convey power and controlsignals to the carriage 43 and robotic arms 39 mounted thereon.

The table base 46 serves a similar function as the cart base 15 in thecart 11 shown in FIG. 2 , housing heavier components to balance thetable/bed 38, the column 37, the carriages 43, and the robotic arms 39.The table base 46 may also incorporate rigid casters to providestability during procedures. Deployed from the bottom of the table base46, the casters may extend in opposite directions on both sides of thebase 46 and retract when the system 36 needs to be moved.

With continued reference to FIG. 6 , the system 36 may also include atower (not shown) that divides the functionality of the system 36between the table and the tower to reduce the form factor and bulk ofthe table. As in earlier disclosed embodiments, the tower may be providea variety of support functionalities to the table, such as processing,computing, and control capabilities, power, fluidics, and/or optical andsensor processing. The tower may also be movable to be positioned awayfrom the patient to improve physician access and de-clutter theoperating room. Additionally, placing components in the tower allows formore storage space in the table base 46 for potential stowage of therobotic arms 39. The tower may also include a console that provides botha user interface for user input, such as keyboard and/or pendant, aswell as a display screen (or touchscreen) for preoperative andintraoperative information, such as real-time imaging, navigation, andtracking information.

In some embodiments, a table base may stow and store the robotic armswhen not in use. FIG. 7 illustrates a system 47 that stows robotic armsin an embodiment of the table-based system. In the system 47, carriages48 may be vertically translated into base 49 to stow robotic arms 50,arm mounts 51, and the carriages 48 within the base 49. Base covers 52may be translated and retracted open to deploy the carriages 48, armmounts 51, and robotic arms 50 around column 53, and closed to stow toprotect them when not in use. The base covers 52 may be sealed with amembrane 54 along the edges of its opening to prevent dirt and fluidingress when closed.

FIG. 8 illustrates an embodiment of a robotically-enabled table-basedsystem configured for a ureteroscopic procedure. In a ureteroscopy, thetable 38 may include a swivel portion 55 for positioning a patientoff-angle from the column 37 and table base 46. The swivel portion 55may rotate or pivot around a pivot point (e.g., located below thepatient's head) in order to position the bottom portion of the swivelportion 55 away from the column 37. For example, the pivoting of theswivel portion 55 allows a C-arm (not shown) to be positioned over thepatient's lower abdomen without competing for space with the column (notshown) below table 38. By rotating the carriage 35 (not shown) aroundthe column 37, the robotic arms 39 may directly insert a ureteroscope 56along a virtual rail 57 into the patient's groin area to reach theurethra. In a ureteroscopy, stirrups 58 may also be fixed to the swivelportion 55 of the table 38 to support the position of the patient's legsduring the procedure and allow clear access to the patient's groin area.

In a laparoscopic procedure, through small incision(s) in the patient'sabdominal wall, minimally invasive instruments (elongated in shape toaccommodate the size of the one or more incisions) may be inserted intothe patient's anatomy. After inflation of the patient's abdominalcavity, the instruments, often referred to as laparoscopes, may bedirected to perform surgical tasks, such as grasping, cutting, ablating,suturing, etc. FIG. 9 illustrates an embodiment of a robotically-enabledtable-based system configured for a laparoscopic procedure. As shown inFIG. 9 , the carriages 43 of the system 36 may be rotated and verticallyadjusted to position pairs of the robotic arms 39 on opposite sides ofthe table 38, such that laparoscopes 59 may be positioned using the armmounts 45 to be passed through minimal incisions on both sides of thepatient to reach his/her abdominal cavity.

To accommodate laparoscopic procedures, the robotically-enabled tablesystem may also tilt the platform to a desired angle. FIG. 10illustrates an embodiment of the robotically-enabled medical system withpitch or tilt adjustment. As shown in FIG. 10 , the system 36 mayaccommodate tilt of the table 38 to position one portion of the table ata greater distance from the floor than the other. Additionally, the armmounts 45 may rotate to match the tilt such that the robotic arms 39maintain the same planar relationship with the table 38. To accommodatesteeper angles, the column 37 may also include telescoping portions 60that allow vertical extension of the column 37 to keep the table 38 fromtouching the floor or colliding with the table base 46.

FIG. 11 provides a detailed illustration of the interface between thetable 38 and the column 37. Pitch rotation mechanism 61 may beconfigured to alter the pitch angle of the table 38 relative to thecolumn 37 in multiple degrees of freedom. The pitch rotation mechanism61 may be enabled by the positioning of orthogonal axes 1, 2 at thecolumn-table interface, each axis actuated by a separate motor 2, 4responsive to an electrical pitch angle command. Rotation along onescrew 5 would enable tilt adjustments in one axis 1, while rotationalong the other screw 6 would enable tilt adjustments along the otheraxis 2.

For example, pitch adjustments are particularly useful when trying toposition the table in a Trendelenburg position, i.e., position thepatient's lower abdomen at a higher position from the floor than thepatient's upper abdomen, for lower abdominal surgery. The Trendelenburgposition causes the patient's internal organs to slide towards his/herupper abdomen through the force of gravity, clearing out the abdominalcavity for minimally invasive tools to enter and perform lower abdominalsurgical procedures, such as laparoscopic prostatectomy.

C. Instrument Driver & Interface

The end effectors of the system's robotic arms may comprise (i) aninstrument driver (alternatively referred to as “instrument drivemechanism” or “instrument device manipulator”) that incorporateselectro-mechanical means for actuating the medical instrument and (ii) aremovable or detachable medical instrument which may be devoid of anyelectro-mechanical components, such as motors. This dichotomy may bedriven by the need to sterilize medical instruments used in medicalprocedures, and the inability to adequately sterilize expensive capitalequipment due to their intricate mechanical assemblies and sensitiveelectronics. Accordingly, the medical instruments may be designed to bedetached, removed, and interchanged from the instrument driver (and thusthe system) for individual sterilization or disposal by the physician orthe physician's staff. In contrast, the instrument drivers need not bechanged or sterilized, and may be draped for protection.

FIG. 12 illustrates an example instrument driver. Positioned at thedistal end of a robotic arm, instrument driver 62 comprises one or moredrive units 63 arranged with parallel axes to provide controlled torqueto a medical instrument via drive shafts 64. Each drive unit 63comprises an individual drive shaft 64 for interacting with theinstrument, a gear head 65 for converting the motor shaft rotation to adesired torque, a motor 66 for generating the drive torque, an encoder67 to measure the speed of the motor shaft and provide feedback to thecontrol circuitry, and control circuity 68 for receiving control signalsand actuating the drive unit. Each drive unit 63 being independentlycontrolled and motorized, the instrument driver 62 may provide multiple(four as shown in FIG. 12 ) independent drive outputs to the medicalinstrument. In operation, the control circuitry 68 would receive acontrol signal, transmit a motor signal to the motor 66, compare theresulting motor speed as measured by the encoder 67 with the desiredspeed, and modulate the motor signal to generate the desired torque.

For procedures that require a sterile environment, the robotic systemmay incorporate a drive interface, such as a sterile adapter connectedto a sterile drape, that sits between the instrument driver and themedical instrument. The chief purpose of the sterile adapter is totransfer angular motion from the drive shafts of the instrument driverto the drive inputs of the instrument while maintaining physicalseparation, and thus sterility, between the drive shafts and driveinputs. Accordingly, an example sterile adapter may comprise a series ofrotational inputs and outputs intended to be mated with the drive shaftsof the instrument driver and drive inputs on the instrument. Connectedto the sterile adapter, the sterile drape, comprised of a thin, flexiblematerial such as transparent or translucent plastic, is designed tocover the capital equipment, such as the instrument driver, robotic arm,and cart (in a cart-based system) or table (in a table-based system).Use of the drape would allow the capital equipment to be positionedproximate to the patient while still being located in an area notrequiring sterilization (i.e., non-sterile field). On the other side ofthe sterile drape, the medical instrument may interface with the patientin an area requiring sterilization (i.e., sterile field).

D. Medical Instrument

FIG. 13 illustrates an example medical instrument with a pairedinstrument driver. Like other instruments designed for use with arobotic system, medical instrument 70 comprises an elongated shaft 71(or elongate body) and an instrument base 72. The instrument base 72,also referred to as an “instrument handle” due to its intended designfor manual interaction by the physician, may generally compriserotatable drive inputs 73, e.g., receptacles, pulleys or spools, thatare designed to be mated with drive outputs 74 that extend through adrive interface on instrument driver 75 at the distal end of robotic arm76. When physically connected, latched, and/or coupled, the mated driveinputs 73 of the instrument base 72 may share axes of rotation with thedrive outputs 74 in the instrument driver 75 to allow the transfer oftorque from the drive outputs 74 to the drive inputs 73. In someembodiments, the drive outputs 74 may comprise splines that are designedto mate with receptacles on the drive inputs 73.

The elongated shaft 71 is designed to be delivered through either ananatomical opening or lumen, e.g., as in endoscopy, or a minimallyinvasive incision, e.g., as in laparoscopy. The elongated shaft 66 maybe either flexible (e.g., having properties similar to an endoscope) orrigid (e.g., having properties similar to a laparoscope) or contain acustomized combination of both flexible and rigid portions. Whendesigned for laparoscopy, the distal end of a rigid elongated shaft maybe connected to an end effector comprising a jointed wrist formed from aclevis with an axis of rotation and a surgical tool, such as, forexample, a grasper or scissors, that may be actuated based on force fromthe tendons as the drive inputs rotate in response to torque receivedfrom the drive outputs 74 of the instrument driver 75. When designed forendoscopy, the distal end of a flexible elongated shaft may include asteerable or controllable bending section that may be articulated andbent based on torque received from the drive outputs 74 of theinstrument driver 75.

Torque from the instrument driver 75 is transmitted down the elongatedshaft 71 using tendons within the elongated shaft 71. These individualtendons, such as pull wires, may be individually anchored to individualdrive inputs 73 within the instrument handle 72. From the handle 72, thetendons are directed down one or more pull lumens within the elongatedshaft 71 and anchored at the distal portion of the elongated shaft 71.In laparoscopy, these tendons may be coupled to a distally mounted endeffector, such as a wrist, grasper, or scissor. Under such anarrangement, torque exerted on drive inputs 73 would transfer tension tothe tendon, thereby causing the end effector to actuate in some way. Inlaparoscopy, the tendon may cause a joint to rotate about an axis,thereby causing the end effector to move in one direction or another.Alternatively, the tendon may be connected to one or more jaws of agrasper at the distal end of the elongated shaft 71, where tension fromthe tendon causes the grasper to close.

In endoscopy, the tendons may be coupled to a bending or articulatingsection positioned along the elongated shaft 71 (e.g., at the distalend) via adhesive, control ring, or other mechanical fixation. Whenfixedly attached to the distal end of a bending section, torque exertedon the drive inputs 73 would be transmitted down the tendons, causingthe softer, bending section (sometimes referred to as the articulablesection or region) to bend or articulate. Along the non-bendingsections, it may be advantageous to spiral or helix the individual pulllumens that direct the individual tendons along (or inside) the walls ofthe endoscope shaft to balance the radial forces that result fromtension in the pull wires. The angle of the spiraling and/or spacingtherebetween may be altered or engineered for specific purposes, whereintighter spiraling exhibits lesser shaft compression under load forces,while lower amounts of spiraling results in greater shaft compressionunder load forces, but limits bending. On the other end of the spectrum,the pull lumens may be directed parallel to the longitudinal axis of theelongated shaft 71 to allow for controlled articulation in the desiredbending or articulable sections.

In endoscopy, the elongated shaft 71 houses a number of components toassist with the robotic procedure. The shaft 71 may comprise a workingchannel for deploying surgical tools, irrigation, and/or aspiration tothe operative region at the distal end of the shaft 71. The shaft 71 mayalso accommodate wires and/or optical fibers to transfer signals to/froman optical assembly at the distal tip, which may include an opticalcamera. The shaft 71 may also accommodate optical fibers to carry lightfrom proximally-located light sources, such as light emitting diodes, tothe distal end of the shaft 71.

At the distal end of the instrument 70, the distal tip may also comprisethe opening of a working channel for delivering tools for diagnosticand/or therapy, irrigation, and aspiration to an operative site. Thedistal tip may also include a port for a camera, such as a fiberscope ora digital camera, to capture images of an internal anatomical space.Relatedly, the distal tip may also include ports for light sources forilluminating the anatomical space when using the camera.

In the example of FIG. 13 , the drive shaft axes, and thus the driveinput axes, are orthogonal to the axis of the elongated shaft 71. Thisarrangement, however, complicates roll capabilities for the elongatedshaft 71. Rolling the elongated shaft 71 along its axis while keepingthe drive inputs 73 static results in undesirable tangling of thetendons as they extend off the drive inputs 73 and enter pull lumenswithin the elongate shaft 71. The resulting entanglement of such tendonsmay disrupt any control algorithms intended to predict movement of theflexible elongate shaft 71 during an endoscopic procedure.

FIG. 14 illustrates an alternative design for an instrument driver andinstrument where the axes of the drive units are parallel to the axis ofthe elongated shaft of the instrument. As shown, a circular instrumentdriver 80 comprises four drive units with their drive outputs 81 alignedin parallel at the end of a robotic arm 82. The drive units, and theirrespective drive outputs 81, are housed in a rotational assembly 83 ofthe instrument driver 80 that is driven by one of the drive units withinthe assembly 83. In response to torque provided by the rotational driveunit, the rotational assembly 83 rotates along a circular bearing thatconnects the rotational assembly 83 to the non-rotational portion 84 ofthe instrument driver 80. Power and controls signals may be communicatedfrom the non-rotational portion 84 of the instrument driver 80 to therotational assembly 83 through electrical contacts that may bemaintained through rotation by a brushed slip ring connection (notshown). In other embodiments, the rotational assembly 83 may beresponsive to a separate drive unit that is integrated into thenon-rotatable portion 84, and thus not in parallel to the other driveunits. The rotational mechanism 83 allows the instrument driver 80 torotate the drive units, and their respective drive outputs 81, as asingle unit around an instrument driver axis 85.

Like earlier disclosed embodiments, an instrument 86 may comprise of anelongated shaft portion 88 and an instrument base 87 (shown with atransparent external skin for discussion purposes) comprising aplurality of drive inputs 89 (such as receptacles, pulleys, and spools)that are configured to receive the drive outputs 81 in the instrumentdriver 80. Unlike prior disclosed embodiments, the instrument shaft 88extends from the center of the instrument base 87 with an axissubstantially parallel to the axes of the drive inputs 89, rather thanorthogonal as in the design of FIG. 13 .

When coupled to the rotational assembly 83 of the instrument driver 80,the medical instrument 86, comprising instrument base 87 and instrumentshaft 88, rotates in combination with the rotational assembly 83 aboutthe instrument driver axis 85. Since the instrument shaft 88 ispositioned at the center of instrument base 87, the instrument shaft 88is coaxial with instrument driver axis 85 when attached. Thus, rotationof the rotational assembly 83 causes the instrument shaft 88 to rotateabout its own longitudinal axis. Moreover, as the instrument base 87rotates with the instrument shaft 88, any tendons connected to the driveinputs 89 in the instrument base 87 are not tangled during rotation.Accordingly, the parallelism of the axes of the drive outputs 81, driveinputs 89, and instrument shaft 88 allows for the shaft rotation withouttangling any control tendons.

E. Navigation and Control

Traditional endoscopy may involve the use of fluoroscopy (e.g., as maybe delivered through a C-arm) and other forms of radiation-based imagingmodalities to provide endoluminal guidance to an operator physician. Incontrast, the robotic systems contemplated by this disclosure canprovide for non-radiation-based navigational and localization means toreduce physician exposure to radiation and reduce the amount ofequipment within the operating room. As used herein, the term“localization” may refer to determining and/or monitoring the positionof objects in a reference coordinate system. Technologies such aspreoperative mapping, computer vision, real-time EM tracking, and robotcommand data may be used individually or in combination to achieve aradiation-free operating environment. In other cases, whereradiation-based imaging modalities are still used, the pre-operativemapping, computer vision, real-time EM tracking, and robot command datamay be used individually or in combination to improve upon theinformation obtained solely through radiation-based imaging modalities.

FIG. 15 is a block diagram illustrating a localization system 90 thatestimates a location of one or more elements of the robotic system, suchas the location of the instrument, in accordance to an exampleembodiment. The localization system 90 may be a set of one or morecomputer devices configured to execute one or more instructions. Thecomputer devices may be embodied by a processor (or processors) andcomputer-readable memory in one or more components discussed above. Byway of example and not limitation, the computer devices may be in thetower 30 shown in FIG. 1 , the cart 11 shown in FIGS. 1-4 , the bedsshown in FIGS. 5-10 , etc.

As shown in FIG. 15 , the localization system 90 may include alocalization module 95 that processes input data 91-94 to generatelocation data 96 for the distal tip of a medical instrument. Thelocation data 96 may be data or logic that represents a location and/ororientation of the distal end of the instrument relative to a frame ofreference. The frame of reference can be a frame of reference relativeto the anatomy of the patient or to a known object, such as an EM fieldgenerator (see discussion below for the EM field generator).

The various input data 91-94 are now described in greater detail.Preoperative mapping may be accomplished through the use of thecollection of low dose CT scans. Preoperative CT scans generatetwo-dimensional images, each representing a “slice” of a cutaway view ofthe patient's internal anatomy. When analyzed in the aggregate,image-based models for anatomical cavities, spaces and structures of thepatient's anatomy, such as a patient lung network, may be generated.Techniques such as center-line geometry may be determined andapproximated from the CT images to develop a three-dimensional volume ofthe patient's anatomy, referred to as preoperative model data 91. Theuse of center-line geometry is discussed in U.S. patent application Ser.No. 14/523,760, the contents of which are herein incorporated in itsentirety. Network topological models may also be derived from theCT-images, and are particularly appropriate for bronchoscopy.

In some embodiments, the instrument may be equipped with a camera toprovide vision data (or image data) 92. The localization module 95 mayprocess the vision data 92 to enable one or more vision-based (or imagedata) location tracking modules or features. For example, thepreoperative model data may be used in conjunction with the vision data92 to enable computer vision-based tracking of the medical instrument(e.g., an endoscope or an instrument advance through a working channelof the endoscope). For example, using the preoperative model data 91,the robotic system may generate a library of expected endoscopic imagesfrom the model based on the expected path of travel of the endoscope,each image linked to a location within the model. Intraoperatively, thislibrary may be referenced by the robotic system in order to comparereal-time images captured at the camera (e.g., a camera at a distal endof the endoscope) to those in the image library to assist localization.

Other computer vision-based tracking techniques use feature tracking todetermine motion of the camera, and thus the endoscope. Some feature ofthe localization module 95 may identify circular geometries in thepreoperative model data 91 that correspond to anatomical lumens andtrack the change of those geometries to determine which anatomical lumenwas selected, as well as the relative rotational and/or translationalmotion of the camera. Use of a topological map may further enhancevision-based algorithms or techniques.

Optical flow, another computer vision-based technique, may analyze thedisplacement and translation of image pixels in a video sequence in thevision data 92 to infer camera movement. Through the comparison ofmultiple frames over multiple iterations, movement and location of thecamera (and thus the endoscope) may be determined.

The localization module 95 may use real-time EM tracking to generate areal-time location of the endoscope in a global coordinate system thatmay be registered to the patient's anatomy, represented by thepreoperative model. In EM tracking, an EM sensor (or tracker) comprisingone or more sensor coils embedded in one or more locations andorientations in a medical instrument (e.g., an endoscopic tool) measuresthe variation in the EM field created by one or more static EM fieldgenerators positioned at a known location. The location informationdetected by the EM sensors is stored as EM data 93. The EM fieldgenerator (or transmitter), may be placed close to the patient to createa low intensity magnetic field that the embedded sensor may detect. Themagnetic field induces small currents in the sensor coils of the EMsensor, which may be analyzed to determine the distance and anglebetween the EM sensor and the EM field generator. These distances andorientations may be intraoperatively “registered” to the patient anatomy(e.g., the preoperative model) in order to determine the geometrictransformation that aligns a single location in the coordinate systemwith a position in the preoperative model of the patient's anatomy. Onceregistered, an embedded EM tracker in one or more positions of themedical instrument (e.g., the distal tip of an endoscope) may providereal-time indications of the progression of the medical instrumentthrough the patient's anatomy.

Robotic command and kinematics data 94 may also be used by thelocalization module 95 to provide localization data 96 for the roboticsystem. Device pitch and yaw resulting from articulation commands may bedetermined during preoperative calibration. Intraoperatively, thesecalibration measurements may be used in combination with known insertiondepth information to estimate the position of the instrument.Alternatively, these calculations may be analyzed in combination withEM, vision, and/or topological modeling to estimate the position of themedical instrument within the network.

As FIG. 15 shows, a number of other input data can be used by thelocalization module 95. For example, although not shown in FIG. 15 , aninstrument utilizing shape-sensing fiber can provide shape data that thelocalization module 95 can use to determine the location and shape ofthe instrument.

The localization module 95 may use the input data 91-94 incombination(s). In some cases, such a combination may use aprobabilistic approach where the localization module 95 assigns aconfidence weight to the location determined from each of the input data91-94. Thus, where the EM data may not be reliable (as may be the casewhere there is EM interference) the confidence of the locationdetermined by the EM data 93 can be decrease and the localization module95 may rely more heavily on the vision data 92 and/or the roboticcommand and kinematics data 94.

As discussed above, the robotic systems discussed herein may be designedto incorporate a combination of one or more of the technologies above.The robotic system's computer-based control system, based in the tower,bed and/or cart, may store computer program instructions, for example,within a non-transitory computer-readable storage medium such as apersistent magnetic storage drive, solid state drive, or the like, that,upon execution, cause the system to receive and analyze sensor data anduser commands, generate control signals throughout the system, anddisplay the navigational and localization data, such as the position ofthe instrument within the global coordinate system, anatomical map, etc.

2. Medical Instrument Compression Compensation

Embodiments of the disclosure relate to systems and techniques forcompensating for compression of medical instruments. Medical instrumentscan include elongated shafts that experience compression whenarticulated. As described herein, the medical instruments can beattached to instrument positioning devices that are configured to movethe medical instruments to compensate for this compression. For example,an instrument positioning device can advance a medical instrument tocompensate for compression in an elongated shaft of the medicalinstrument. In some embodiments, the amount of compression is determinedusing one or more compression compensation parameters. The one or morecompression compensation parameters can be determined during calibrationof the medical instrument.

A. Compression of a Medical Instrument

FIG. 16A illustrates an embodiment of an elongated shaft 101 of amedical instrument 100. The elongated shaft 101 is configured forinsertion, in use, into a body of a patient. In some embodiments, theelongated shaft 101 is configured for insertion, for example, via alaparoscopic procedure, into a cavity of the patient. In someembodiments, the elongated shaft 101 is configured for insertion, forexample, via an endoscopic procedure, into a lumen (or luminal network)of the patient. As shown in the embodiment of FIG. 17A, the medicalinstrument 100 may also include an instrument base 111 (or handle) thatis configured to couple the medical instrument 100 to an instrumentdriver 113 of an instrument positioning device 115, such as a roboticarm.

The elongated shaft 101 may be articulable (or steerable). That is, anoperator may control the pose, shape, and/or articulation of theelongated shaft 101. This may allow the operator to guide or navigatethe elongated shaft 101 within the patient's body. In some embodiments,the medical instrument 100 is robotically controllable as describedabove. A remote operator may provide control signals or inputs to aninstrument positioning device that manipulates (e.g., steers,articulates, inserts, etc.) the elongated shaft 101. The elongated shaft101 may be formed from a flexible or bendable material. In theillustrated embodiment, the elongated shaft 101 extends between a distalportion 103 and a proximal portion 105. The distal portion 103 mayinclude a distal tip. The distal portion 103 may be the leading end ofthe elongated shaft 101 (i.e., the end that is inserted, in use, intothe patient). The proximal end 105 may connect (either removably orpermanently) to the instrument base 111 (see FIG. 17A).

The medical instrument 100 can include pull wires (or tendons) thatextend through one or more sections of the elongated shaft 101. Asdescribed above, the pull wires are actuable to control the pose, shape,and/or articulation of the elongated shaft 101. In the illustratedembodiment, two pull wires 107, 109 extend through the elongated shaft101. Although the two pull wires 107, 109 are illustrated, the medicalinstrument 100 may include other numbers of pull wires. For example, themedical instrument 100 can include one, two, three, four, five, six, ormore pull wires. In the illustrated embodiment, the pull wires 107, 109extend through (i.e., within) the elongated shaft 101. In anotherexample, the pull wires 107, 109 may extend along an exterior of theelongated shaft 101. Further, although the pull wires 107, 109 areillustrated extending straight (i.e., along a linear path) through theelongated shaft 101, in other embodiments, the pull wires 107, 109 mayinclude one or more spiraled, coiled, or helical sections.

In one example, the pull wires 107, 109 may be coupled to the distal end103 of the elongated shaft 101. In another example (not shown), the pullwires 107, 109 may be coupled to position located proximally relative tothe distal end 103 of the elongated shaft 101. At the proximal end 105,the pull wires 107, 109 can extend into the instrument base 111 (seeFIG. 17A). Within the instrument base 111, the pull wires 107, 109 canbe coupled to drive inputs (such as drive inputs 81 described above)that are configured actuate (i.e., tension or pull) the pull wires 107,109. In some embodiments, each pull wire 107, 109 is coupled to anindependently operable drive input. When the medical instrument 100 iscoupled to the instrument driver 113 of the instrument positioningdevice 115, the drive inputs engage with corresponding drive outputs onthe instrument positioning device 115 as described above. The driveoutputs can actuate the drive inputs so as to robotically controlactuation of the pull wires 107, 109.

As discussed throughout this disclosure, the elongated shaft 101 mayexperience compression as it is articulated or moved to variouspositions, poses, or shapes. The compression may be axial compression(i.e., compression measured along a longitudinal axis of the elongatedshaft 101). The compression may be caused by pull wire-based movements.In other words, actuation (i.e., pulling or tensioning) the pull wires107, 109 to control articulation, pose, and/or shape of the elongatedshaft 101 may cause compression of the elongated shaft 101.

In some instances, compression of the elongated shaft 101 may beundesirable. For example, an operator may command an articulation (e.g.,bending) of the elongated shaft 101. In addition to the commandedarticulation, however, the elongated shaft 101 may also experiencecompression, resulting in an unexpected or undesired position of thedistal end 103 of the elongated shaft 101. This may cause difficultiesfor the operator while driving (e.g., guiding or controlling) themedical instrument 100. This may also cause inaccuracy in a roboticnavigation system used to drive and/or monitor the position of themedical instrument 100. For example, the robotic navigation system canuse telemetry data from the instrument positioning device(s) 115 todetermine or estimate a position (for example, the position of a distaltip or portion) of the medical instrument 100 within the body.Compression of the elongated body, if unaccounted for, can cause therobotic navigation system to may not accurately determine or estimatethe position of the medical instrument 100. For example, if compressionis not accounted for, the robotic navigation system may determine orestimate that the distal tip is more inserted into the body than itactually is.

In FIG. 16A, the elongated shaft 101 is illustrated in a default oruncompressed state. In the default state, the elongated shaft 101 has alength L measured between the distal end 103 and the proximal end 105.As will be discussed below, compression of the elongated shaft 101 mayresult in a decreasing the length L.

For ease of illustration and clarity, various other features of themedical instrument 100 are omitted in FIG. 16A. For example, the medicalinstrument 100 may also include a working channel, imaging device(s)(e.g., one or more cameras), spatial sensor(s) (e.g., position sensors,orientations sensors), etc.

FIG. 16B depicts the elongated shaft 101 of the medical instrument 100experiencing axial compression caused by an example of pull wire-basedmovement. In the illustrated example, a force F has been applied to thepull wire 107 in the illustrated direction. As illustrated, the force Fcauses a tension or displacement of the pull wire 107 that causes theelongated shaft 101 to articulate or bend to an angle α, as shown. Thistype of pull-wire based movement may be used by an operator to steer orturn the medical instrument 100. In addition to the articulation of theelongated shaft 101 to the angle α, the tension or displacement of thepull wire 107 also causes an axial compression of the elongated shaft101. In the illustrated embodiment, the distal portion 103 of theelongated shaft 101 has axially compressed or retracted a distance C, asshown. That is, the length L of the elongated shaft 101 is reduced bythe distance C in response to the pull wire-based movement (i.e.,articulation to the angle α) of the elongated shaft 101. As mentionedabove, this may result in the distal portion 103 of the elongated shaft101 being out of position. This axial compression may be undesirable.

FIG. 16C depicts the elongated shaft 101 of the medical instrument 100experiencing axial compression caused by another example of pull-wirebased movement. In this example, both pull wires 107, 109 are actuatedequally by the force F. Because both pull wires 107, 109 are actuatedequally, the elongated shaft 101 experiences compression withoutbending. In the illustrated example, the length L of the elongated shaft101 is axially compressed by a distance C as shown. This type ofpull-wire based movement may be used by an operator to increase thestiffness or sensitivity of the elongated shaft 101. In some instances,however, the operator may desire to increase the stiffness orsensitivity of the elongated shaft 101 without changing the position ofthe distal portion 103 of the elongated shaft 101, and thus, the axialcompression illustrated in FIG. 16C may be undesirable.

As described in further detail below, according to the presentdisclosure, axial compressions caused by pull-wire based movements (asillustrated, for example, in FIGS. 16B and 16C) can be compensated for,allowing for increased movement accuracy and an improved drivingexperience of medical instruments 100 including elongated shafts 101.

B. Compression Compensation

Compression of the elongated shaft 101 of the medical instrument 100 maybe compensated for by moving (e.g., advancing or retracting) the medicalinstrument 100 with the instrument positioning device 115 (e.g., arobotic arm) to which it is coupled. For example, the extent or amount(e.g., length) of compression (e.g., along a longitudinal axis) can becalculated, determined, or estimated, and the instrument positioningdevice 115 can advance the medical instrument 100 a corresponding amountsuch that the distal portion 103 of the elongated shaft 101 remains inthe expected position. In other words, the instrument positioning device115 can advance the medical instrument 100 an amount corresponding tothe amount of compression such that the distal portion 103 is located ina position that corresponds to the position of the distal portion 103 inthe absence of the axial compression.

FIG. 17A illustrates the medical instrument 100 coupled to an embodimentof an instrument positioning device 115. As shown, the medicalinstrument 100 includes the elongated shaft 101 extending between adistal portion 103 and a proximal portion 105. The proximal portion 105is coupled (either removably or permanently) to the instrument base 111.The instrument base 111 is coupled to the instrument driver 113 of theinstrument positioning device 115. In FIG. 17A, only a portion of theinstrument positioning device 115 is shown. The instrument positioningdevice 115 may comprise a robotic arm, such as any of the robotic arms12, 39, 61 shown in FIGS. 1-15 described above. As mentioned above, theinstrument driver 113 can include drive outputs for actuating the driveinputs in the instrument base 111 to actuate the pull wires 107, 109.The instrument positioning device 115 is movable to insert (or advance)or retract the elongated shaft 101 of the medical instrument device 100within the patient.

FIG. 17B depicts an example of the instrument positioning device 115configured to move to compensate for axial compression caused by pullwire-based movement of the medical instrument 100. In FIG. 17B, theelongated shaft 101 is illustrated undergoing pull wire-based movementas shown and described in FIG. 16B, which causes a compression C of theelongated shaft 101. As shown in the example of FIG. 17B, the instrumentposition device 115 can move a distance D in the direction illustrated(i.e., advancing the elongated shaft 101) to compensate for thecompression C. In the illustrated example, the distance D is equal tothe distance of the compression C, such that the position of the distalportion 103 is advanced to the position it would have been in absent thecompression. As shown, the elongated shaft 101 is articulated to theangle α and advanced the distance D to compensate for the compression C.

FIG. 17C depicts an example of the instrument positioning device 115configured to move to compensate for axial compression caused by anothertype of pull wire-based movement of the medical instrument 100. In FIG.17C, the elongated shaft 101 is illustrated undergoing pull wire-basedmovement as shown and described in FIG. 16C, which causes a compressionC of the elongated shaft 101. As shown in the example of FIG. 17C, theinstrument position device 115 can move a distance D in the directionillustrated (i.e., advancing the elongated shaft 101) to compensate forthe compression C. In the illustrated example, the distance D is equalto the distance of the compression C, such that the position of thedistal portion 103 is advanced to the position it would have been inabsent the compression.

FIG. 18 is a flow chart illustrating an example method 200 forcompensating for compression in a medical instrument 100. The method 200begins at block 202 at which a commanded pull-wire based movement of themedical instrument 100 is received. The commanded pull wire-basedmovement may be received from an operator. The operator may provide thecommanded pull-wire based movement using a remotely located inputdevice. The commanded pull wire-based movement can be executed by theinstrument positioning device 115.

Next, the method 200 moves to block 204 at which the compression of themedical instrument 100 caused by the commanded pull wire-based movementis determined. In one example, determining the compression comprisesmeasuring the compression. In another example, determining thecompression comprises calculating the compression. In another example,determining the compression comprises estimating the compression.

As will be discussed in further detail below, the compression may bedetermined, calculated, or estimated using one or more compressioncompensation parameters. The compression compensation parameter and itsuse are discussed in further detail below in section II.C.

In conjunction with using one or more compression compensationparameters, the compression of the medical instrument 100 can bedetermined, calculated, or estimated based on data from one or moreother techniques. In one example, fluoroscopic images of the medicalinstrument 100 can be analyzed to determine compression, in addition tothe use of the compression compensation parameters. In another example,the medical instrument 100 can include one or more spatial sensors(e.g., EM sensors) positioned thereon. The spatial sensors may provideposition data regarding the position of the medical instrument 100. Thisposition data can be analyzed to determine the compression of themedical instrument 100, in addition to the use of the compressioncompensation parameters. In another example, the medical instrument 100can include a shape-sensing fiber. The shape-sensing fiber can providedata about the shape or pose of the medical instrument 100. This datacan be analyzed to determine the compression of the medical instrument100, in addition to the use of the compression compensation parameters.In another example, the compression of the medical instrument 100 isdetermined using a model, e.g., based on the shape, size, and materialproperties of the elongated shaft of the medical instrument 100, inaddition to the use of the compression compensation parameters. In oneexample of determining compression of the medical instrument 100 using amodel, the elongated shaft 101 of the medical instrument 100 can bedivided into one or more sections that can be modeled usingEuler-Bernoulli beam theory.

In another example, the compression of a first medical instrument can bemeasured relative to a second medical instrument, in addition to the useof the compression compensation parameters. As described below insection II.D, two or more medical instruments can be configured fortelescoping use. That is, a second medical instrument can telescopewithin a working channel of the first medical instrument. The firstmedical instrument can include a spatial sensor located at its distalportion. The second medical instrument can include a spatial sensorlocated at its distal portion. The compression can be determined orestimated by comparing the relative position of these two positionsensors. This may ensure or increase the likelihood that the distalportions of the two medical instruments remain aligned (i.e., flush).

At block 206 of the method 200, the instrument positioning device 115that is coupled to the medical instrument 100 is moved (e.g., advancedor retracted) to compensate for the compression determined at block 204.In some instances, the instrument positioning device 115 advances themedical instrument 100 further into the patient's body to compensate forthe determined compression. In one example, the distance advanced intothe patient body is approximately equal to the determined compression.In another example, the distance advanced is less than the determinedcompression. In another example, the distance advanced is greater thanthe determined compression. As described below in section II.D, inembodiments that include telescoping medical instruments, one medicalinstrument can be retracted to compensate for the compression, the othermedical instrument can be advanced to compensate for the compression, orone medical instrument can be advanced and the other medical instrumentcan be retracted to compensate for the compression.

In some embodiments, block 206 is performed substantially at the sametime as the pull wire-based movement is executed. That is, theinstrument positioning device 115 advances or retracts to compensate forthe compression at substantially the same time as the pull wires areactuated to perform the pull wire-based movement. In some embodiments,this maintains or helps to maintain the correct or desired positioningof the distal portion 103 of the elongated shaft 101 throughout thecommanded pull wire-based movement.

In some embodiments, the blocks 202, 204, 206 of the method 200 can beperformed in a loop to provide compression compensation for each newlycommanded pull wire-based movement of the medical instrument.

The method 200 can include other blocks or steps in addition to thoseillustrated. In some embodiments, not all illustrated blocks of themethod 200 need be implemented.

C. Compression Compensation Parameter

The compression of the elongated shaft 101 can be determined,calculated, or estimated using one or more compression compensationparameters. The compression compensation parameter may be determinedduring a calibration of the medical instrument 100. Example calibrationmethods and processes, during which the compression compensationparameter can be determined, are described below in section II.F.

The compression compensation parameter can be specific to a particularor specific medical instrument 100. That is, for a specific medicalinstrument 100, the compression compensation parameter can be determinedduring calibration of that particular medical instrument 100. In thisway, the compression compensation parameter can account for the uniqueproperties (caused by, for example, material variation, manufacturingprocess variation, etc.) of that particular medical instrument 100. Thecompression compensation parameter can be associated with the particularmedical instrument 100. For example, the compression compensationparameter can be stored in a memory or non-transitory computer readablemedium of the medical instrument 100. In some embodiments, thecompression compensation parameter is stored in a remote database andassociated with the particular medical instrument 100 such that it canbe accessed and used to determine compression when the particularmedical instrument 100 is used.

In another example, the compression compensation parameter can bespecific to a class, batch, or model of similar medical instruments 100.That is, the same compression compensation parameter can be used for aclass, batch, or model of similar medical instruments 100. In someembodiments, a single or several medical instruments 100 are calibratedto determine a compression compensation parameter that will be used by alarger group of similar medical instruments 100.

In some embodiments, the compression compensation parameter isdetermined using a model that, for example, takes into account, forexample, the material properties and dimensions of the medicalinstrument 100. In one example, the elongated shaft 101 of the medicalinstrument 100 can be divided into one or more sections that can bemodeled using Euler-Bernoulli beam theory.

The compression compensation parameter can be a value, factor, orparameter that relates a characteristic of the pull wire-based movementto axial compression. As one example, the compression compensationparameter can relate an angle of articulation of the elongated shaft 101of the medical instrument 100 to axial compression. For example, thecompression compensation parameter can relate x degrees of articulationof the elongated shaft 101 to y millimeters of axial compression. Thecompression compensation parameter can relate a commanded angle ofarticulation to axial compression. In another example, the compressioncompensation parameter can relate a measured angle of articulation toaxial compression. In some instances, the angle of articulation ismeasured using spatial sensors (such as EM sensors), shape-sensingfiber, medical imaging (e.g., fluoroscopy), or other methods.

In another example, the compression compensation parameter can relatetension in a pull wire to axial compression of the elongated shaft 101.The medical instrument 100 may include one or more tension sensors formeasuring the tension in the pull wires.

In another example, the compression compensation parameter can relatedisplacement (e.g., linear displacement) of a pull wire to axialcompression of the elongated shaft 101. The medical instrument 100 mayinclude a linear actuator for actuating the pull wire. The compressioncompensation parameter can relate linear movement of the actuator or thepull wire to axial compression of the elongated shaft 101. For example,the compression compensation parameter can relate x millimeters oflinear displacement of the pull wire or actuator to y millimeters ofaxial compression.

In some embodiments, the medical instrument 100 comprises rotationalactuators that actuate the pull wires. For example, the pull wires maybe mounted on pulleys which are rotated to actuate the pull wires. Thecompression compensation parameter can relate rotation of a pulleyaround which the pull wires are wound to axial compression of theelongated shaft. For example, the compression compensation parameter canrelate x degrees of rotation of the pulley to y millimeters of axialcompression.

In the above-cited examples, the compression compensation parameter is aparameter that linearly relates a characteristic of pull wire-basedmovement to axial compression. This need not be the case in allembodiments. For example, in some embodiments, the compressioncompensation parameter can comprise a function that relates thecharacteristic of pull wire-based movement to axial compression, whereinthe function is non-linear.

In some embodiments, only a single compression compensation parameter isassociated with the medical instrument 100. In some embodiments,multiple compression compensation parameters are associated with themedical instrument 100. For example, different compression compensationparameters can be associated with each of the different pull wires. Asanother example, different compression compensation parameters can beused to compensate for pull wire-based movements in differentdirections. As another example, multiple compression compensationparameters could be used to model non-linear compression of theelongated body 101, using, for example polynomial, exponential, or othernon-linear functions. In some instances, the number of compressionparameters and/or the type of function (linear or non-linear) can bevaried to closely model the relationship of compression to the input.

As described above, the compression compensation parameter can be usedto relate one or more characteristics of pull wire-based movement toaxial compression. Thus, the compression compensation parameter can beused to determine, calculate, or estimate axial compression of theelongated shaft 101 for a given pull wire-based movement. In someembodiments, the compression compensation value is used at block 204 ofthe method 200 described above.

D. Compression Compensation in Telescoping Medical Instruments

Although the descriptions above have focused primarily on a singlemedical instruments, the compression compensation methods and systemsdescribed herein can be applied in systems that include telescopingmedical instruments, such as, for example, systems that include a secondmedical instrument that telescopes within a working channel of a firstmedical instrument. The systems and methods may also be applied insystems that include more than two (e.g., three, four, five, or more)telescoping medical instruments.

FIG. 19A illustrates an embodiment of a second medical instrument 120telescoping within a working channel 117 of a first medical instrument100. In the illustrated embodiment, the first medical instrument 100 isconfigured as previously described, including an elongated shaft 101 andan instrument base 111. The elongated shaft 101 includes a workingchannel 117 extending therethrough. The first medical instrument 100 iscoupled to a first instrument driver 113 of a first instrumentpositioning device 115. The first instrument positioning device 115 isconfigured to move to advance or retract the first medical instrument100.

The second medical instrument 120 is configured similar to the firstmedical instrument 100, including an elongated shaft 121 extendingbetween a distal portion 123 and a proximal portion 125. The proximalportion 125 is connected (either removably or permanently) to a secondinstrument base 131. The second instrument base 131 is coupled to asecond instrument driver 133 of a second instrument positioning device135. The second instrument positioning device 135 is configured to moveto advance or retract the second medical instrument 120.

As shown, the elongated shaft 121 of the second medical instrument 120extends through the working channel 117 of the first medical instrument100. The second instrument positioning device 135 is configured to moveto advance or retract the second medical instrument 120 through theworking channel 117 of the first medical instrument 100. Although notillustrated, in some examples, the second medical instrument 120 mayalso include a working channel for receiving a third medical instrument.

In the configuration illustrated in FIG. 19A, the distal portion 123 ofthe second medical instrument 120 is aligned with the distal portion 103of the first medical instrument 100. In some instances, this may be apreferred configuration for driving the medical instruments 100, 120.For example, the first and second medical instruments 100, 120 can be inthis configuration (with distal portions 103, 123 aligned or flush) asthey are navigated through the body to a target site.

The first medical instrument 100 can include pull wires for controllingthe articulation, shape, and/or pose of the first elongated shaft 101.The second medical instrument 120 can include pull wires for controllingthe articulation, shape, and/or pose of the second elongated shaft 121.In other examples, the first medical instrument 100 can be a passiveinstrument that does not include pull wires (i.e., a non-steerableinstrument) or the second medical instrument 120 can be a passiveinstrument that does not include pull wires (i.e., a non-steerableinstrument).

FIG. 19B depicts an example of axial compression of the first and secondmedical instruments 100, 120 caused by pull wire-based movement. In theillustrated example, the first and second medical instruments 100, 120are articulated from the position shown in FIG. 19A to an angle shown inFIG. 19B. Either or both the first and second medical instruments 100,120 can experience compression. In the position illustrated in FIG. 19B,the second elongated shaft 121 extends outwardly from the distal end 103of the first elongated shaft 101. This may be caused by the axialcompression of the first and/or second elongated shafts 101, 121. Thismay be undesirable. For example, as noted above, it is often desirableto drive the first and second medical instruments 100, 120 with thedistal ends 103, 123 positioned flush.

FIG. 19C illustrates that the axial compression illustrated in FIG. 19Bcan be compensated for by moving the first and/or the second instrumentpositioning devices 115, 135 to compensate. To compensate for axialcompression, and return the distal portions 103, 123 to a flushposition, the system can either move the first instrument positioningdevice 115 a distance D1 in the direction indicated to advance the firstmedical instrument 100, move the move the second instrument positioningdevice 115 the distance D2 in the direction indicated to retract thesecond medical instrument 120, or perform a combined movement of thefirst and second instrument positioning devices 115, 135 to both advancethe first medical instrument 100 and retract the second medicalinstrument 120.

In one example, a “compression compensation ratio” (CCR) can be definedor set for each medical instrument 100, 120. The CCR can be a valuebetween zero and one. The CCR is one when the compressed medicalinstrument compensates fully for its own compression and zero when thereciprocal medical instrument (which may be uncompressed or may also bearticulated and compressed) is moved to fully compensate for compressionof the compressed medical instrument. Using the CCR for each medicalinstrument it is possible to define equations for defining the movementor insertion of the first and second medical instruments 100, 120, asfollows:insertion_(2nd)=(1−CCR_(1st))·compression_(1st)−CCR_(2nd)·compression_(2nd)insertion_(1st)=(1−CCR_(2nd))·compression_(2nd)−CCR_(1st)·compression_(1st)

Using the principals and equations described above, as well as CCRs foreach medical instrument 100, 120, it is possible to compensate forcompression of the first and/or second medical instrument 100, 120 bymoving only the first medical instrument 100, by moving only the secondmedical instrument 120, or by moving both medical instruments 100, 120.

In some embodiments, retractions (CCR=0) of the first and second medicalinstruments 100, 120 are preferred. For example, in some instances,retractions of the first and second medical devices 100, 120 may besafer than insertions of the medical instruments. In some embodiments,however, insertions (CCR=1) are possible. Additionally, CCRs betweenzero and one can also be used.

Additionally, the CCR values can influence the spatial path taken by thedistal portion 103, 123 of the first and second medical devices 100,120. For example, a CCR of one may correspond to a more spherical path,while a CCR of zero may create a more obtuse path (along an ellipsoidinstead of a sphere). In some embodiments, the CCR value can be adjustedso that an optimal path can be tuned empirically. In some instances, theCCR value is adjusted during device calibration to deliver a targetmotion path of the distal tip of the elongated body 101. Duringcalibration, adjustment can be performed either manually orautomatically through analysis of tip path.

E. Example Medical Instruments and Systems for Compression Compensation

FIG. 20 illustrates an embodiment of a medical instrument 100 configuredto compensate for axial compression. In the illustrated embodiment, themedical instrument 100 is configured as described above, including, forexample, an elongated shaft 101 extending between a distal portion 103and a proximal portion 105. The elongated shaft 101 may include one ormore pull wires for articulating the elongated shaft. The elongatedshaft 101 is connected to an instrument base 111. The instrument device111 is configured to couple to an instrument driver 113 of an instrumentpositioning device 115. The instrument positioning device 115 can beconfigured to move the medical instrument 100 to advance or retract theelongated shaft 101 within a patient.

As illustrated, for some embodiments, the medical instrument 100includes a computer readable medium 151. The computer readable medium151 can be positioned on or within the instrument base 111. In anotherexample, the computer readable medium 151 can be positioned on or withinthe elongated shaft 101.

The computer readable medium 151 can store information associated withthe medical instrument 100. For example, the computer readable medium151 can store one or more compression calibration parameters asdiscussed above in section II.C.

The computer readable medium 151 can include a computer readable codewhich can be read by another device. For example, the computer readablecode can be a radio frequency identifier (RFID) tag. Data stored in thecomputer readable medium 151, such as the compression compensationparameter, can be accessed by another device by scanning the RFID tagwith an RFID reader. Other types of computer readable codes may also beused, such as bar codes, QR codes, etc.

The medical instrument 100 can include communication circuitry forcommunicating data stored in the computer readable medium 151 to otherdevices. Such communication circuitry may be wired or wireless.

The medical instrument 100 can include one or more EM sensors 157. TheEM sensors 157 are positioned on or within the elongated shaft 101. Asillustrated, an EM sensor 157 is positioned at the distal portion 103 ofthe elongated shaft 101. The EM sensors 157 may be configured to provideposition and/or orientation data about the medical instrument 100. TheEM sensors 157 provide position and/or orientation data relative to anexternally generated EM field. Other types of spatial sensors can alsobe included.

The medical instrument 100 can include a shape-sensing fiber 159. Theshape-sensing fiber 159 may extend along or within the elongated shaft159. The shape-sensing fiber 159 can provide data related to the shape,articulation, or pose of the medical instrument 100.

The medical instrument 100 can include one or more tension sensorsassociated with the one or more pull wires. The tension sensors can beconfigured to provide tension data for the one or more pull wires. Insome embodiments, the tensions sensors are positioned in the instrumentbase 111.

FIG. 21 is a block diagram depicting a system 300 configured tocompensate for compression of medical instruments 100, 120. In theillustrated embodiment, the system 300 includes a processor 302 (or aplurality of processors) connected to a memory or computer readablemedium 304 (or a plurality of computer readable media). The computerreadable medium 304 can include instructions that can be executed by theprocessor 302 to control the system 300.

In the illustrated embodiment, the system 300 includes a firstinstrument positioning device 115 coupled to a first medical instrument100. The first medical instrument 100 includes a computer readable code310. The first instrument positioning device 115 includes a code reader306. The code reader 306 is configured to read the computer readablecode 310 on the first medical instrument 100. In some embodiments, thecomputer readable code 310 is an RFID tag and the reader 306 is a RFIDreader. The computer readable code 310 can store data related to thefirst medical instrument 100, such as compression compensationparameters. The code reader 306 can read the data from the machinereadable code 310. In some embodiments, the data read from the computerreadable code 310 can be communicated to the processor 302 for use incontrolling the system 300.

The system 300 may also include additional instrument positioningdevices coupled to additional medical instruments. For example, asillustrated, the system 300 includes a second instrument positioningdevice 135 coupled to a second medical instrument 120. The secondinstrument positioning device 135 includes a reader 308 configured toread a machine readable code 312 on the second medical instrument 120 inthe manner previously described.

In some embodiments, the system 300 compensates for compression in thefirst and second medical instruments using the method 200 describedabove.

In some embodiments, the second medical instrument 120 telescopes withina working channel of the first medical instrument 100. The system 300may use the CCRs described above to compensate for compression asdescribed in section II.D.

The computer readable medium 304 can include instructions that configurethe processor 302 to cause the system 300 to determine, based at leastin part on information indicative of a pull wire-based movement of anelongated shaft 101 of a first medical instrument 100 and a compressioncompensation parameter, an axial compression of the elongated shaft 101of the first instrument 100. The compression compensation parameter canbe read, using the reader 306, from the computer readable code 310. Theinstructions can further be configured to move the first instrumentpositioning device 115 connected to the first medical instrument 100 tocompensate for the axial compression of the first elongated shaft.

F. Example Calibration Processes

The compression compensation parameter can be determined during acalibration process of the medical instrument 100. The calibrationprocess can include articulating the medical instrument to a firstposition with a pull wire-based movement, determining the compression ofthe medical instrument, and relating a characteristic of the pullwire-based movement to the determined compression to determine thecompression compensation parameter.

The calibration process can include articulating the medical instrument100 to a variety of different positions and determining compression andcompression compensation parameters for each. In some embodiments, asingle compression compensation parameter is derived from the variety ofdifferent articulated positions.

The calibration process can include attaching one or more spatial capsto the medical instrument 100. The one or more spatial caps can becalibrated to provide valid metrology or measurement of the pose (e.g.,position and/or orientation) of the medical instrument 100. In someinstances, the one or more spatial caps are calibrated to providemetrology or measurement or pose of the distal tip of the elongated body101 of the medical instrument 100. The spatial caps can include spatialsensors, such as EM sensors, that provide position and/or orientationdata about the articulation, pose, or position of the medical instrument100. The spatial caps can be used to measure the articulation and/orcompression of the medical instrument 100. The one or more spatial capscan be used to further validate the spatial sensors included on themedical instrument 100.

In other embodiments, feedback from an imaging device included on themedical instrument 100 (for example, at a distal tip of the elongatedbody) can be analyzed using an external tracking device to estimate tippose instead of or in addition to the use of the one or more spatialcaps. Triangulation, projection or direct or manual measurement (e.g.,using a protractor) methods can also be used in addition to or in placeof the one or more spatial caps.

The articulation and/or compression of the medical instrument 100 can bedetermined from spatial sensors positioned on the medical instrument 100itself. For example, the articulation and/or compression can bedetermined using EM sensors or shape-sensing fiber as previouslydescribed.

FIG. 22 is a flow chart illustrating an example method 400 forcalibrating a medical instrument 100. The method 400 begins at block401, where a pull wire-based movement is performed to move the elongatedshaft 101 to a first position. In some instances, articulating theelongated shaft 101 comprises tensioning, pulling, or otherwiseactuating a pull wire connected to a distal portion 103 of the elongatedshaft 101.

The method 400 continues at block 402, where a characteristic of thepull wire-based movement is determined. In some instances, determiningthe characteristic of the pull wire-based movement can include pull wiretension, pull wire displacement, actuator displacement, commanded angleof articulation, measured angle of articulation, etc.

In some examples, the method 400 further includes attaching one or morespatial caps to the distal portion 103 of the elongated shaft 101. Theone or more spatial caps can be configured to provide spatial data aboutthe location and orientation of the distal portion 103 of the elongatedshaft 101. In some embodiments, determining the pull wire-based movementcomprises analyzing the spatial data from the spatial cap. In someembodiments, the one or more spatial caps include one or more EMsensors. In some embodiments, determining the pull wire-based movementcomprises measuring an angle of the elongated shaft.

At block 404, with the elongated shaft 101 in the first position, thecompression of the elongated shaft 101 is determined. In an example,determining the compression can include analyzing the spatial data fromthe spatial cap. In another example, the elongated shaft 101 comprises aspatial sensor configured to provide spatial data about the location andorientation of the distal portion 103 of the elongated shaft 101, anddetermining the pull wire-based movement includes analyzing the spatialdata from the spatial sensor. In another example, determining the axialcompression comprises measuring a length of the elongated shaft.

At block 406, a compression compensation parameter is determined byrelating the first position to the determined compression of theelongated shaft 101. In some embodiments, the method 400 furtherincludes storing the compression compensation parameter in anon-transitory computer readable medium of the first medical instrument100.

3. Implementing Systems and Terminology

Implementations disclosed herein provide systems, methods and apparatusfor compensating for compression in elongated shafts of medicalinstruments. Compression can be determined, in some instances, using acompression compensation parameter determined during calibration of themedical instrument, and compensated for by moving the medical instrumentwith an instrument positioning device coupled thereto.

It should be noted that the terms “couple,” “coupling,” “coupled” orother variations of the word couple as used herein may indicate eitheran indirect connection or a direct connection. For example, if a firstcomponent is “coupled” to a second component, the first component may beeither indirectly connected to the second component via anothercomponent or directly connected to the second component.

The phrases referencing specific computer-implementedprocesses/functions described herein may be stored as one or moreinstructions on a processor-readable or computer-readable medium. Theterm “computer-readable medium” refers to any available medium that canbe accessed by a computer or processor. By way of example, and notlimitation, such a medium may comprise random access memory (RAM),read-only memory (ROM), electrically erasable programmable read-onlymemory (EEPROM), flash memory, compact disc read-only memory (CD-ROM) orother optical disk storage, magnetic disk storage or other magneticstorage devices, or any other medium that can be used to store desiredprogram code in the form of instructions or data structures and that canbe accessed by a computer. It should be noted that a computer-readablemedium may be tangible and non-transitory. As used herein, the term“code” may refer to software, instructions, code or data that is/areexecutable by a computing device or processor.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isrequired for proper operation of the method that is being described, theorder and/or use of specific steps and/or actions may be modifiedwithout departing from the scope of the claims.

As used herein, the term “plurality” denotes two or more. For example, aplurality of components indicates two or more components. The term“determining” encompasses a wide variety of actions and, therefore,“determining” can include calculating, computing, processing, deriving,investigating, looking up (e.g., looking up in a table, a database oranother data structure), ascertaining and the like. Also, “determining”can include receiving (e.g., receiving information), accessing (e.g.,accessing data in a memory) and the like. Also, “determining” caninclude resolving, selecting, choosing, establishing and the like.

The phrase “based on” does not mean “based only on,” unless expresslyspecified otherwise. In other words, the phrase “based on” describesboth “based only on” and “based at least on.”

The previous description of the disclosed implementations is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to these implementations will bereadily apparent to those skilled in the art, and the generic principlesdefined herein may be applied to other implementations without departingfrom the scope of the invention. For example, it will be appreciatedthat one of ordinary skill in the art will be able to employ a numbercorresponding alternative and equivalent structural details, such asequivalent ways of fastening, mounting, coupling, or engaging toolcomponents, equivalent mechanisms for producing particular actuationmotions, and equivalent mechanisms for delivering electrical energy.Thus, the present invention is not intended to be limited to theimplementations shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A robotic system, comprising: a robotic armcomprising: a series of linkages connected by a series of joints; and aninstrument driver coupled to a distal end of the series of linkages; anda medical instrument, comprising: an elongated shaft extending between adistal portion and a proximal portion, the elongated shaft configuredfor insertion, in use, into a lumen of a patient; an instrument baseconnected to the proximal portion of the elongated shaft, the instrumentbase including an attachment interface configured to facilitateattachment to the robotic arm; a non-transitory computer readable mediumstoring a compression compensation parameter that relates movement ofthe elongated shaft to axial compression of the elongated shaft; and apull wire connected to the distal portion of the elongated shaft, thepull wire extending along the elongated shaft between the distal portionand a drive input positioned at the instrument base, the drive inputconfigured to actuate the pull wire to cause movement of the elongatedshaft; wherein the robotic arm is configured to move the instrumentdriver along a virtual rail to advance or retract the instrument basebased at least in part on the stored compression compensation parameter,and wherein the robotic arm moves to advance or retract the instrumentbase at substantially the same time as the drive input actuates the pullwire to cause movement of the elongated shaft.
 2. The robotic system ofclaim 1, wherein movement of the elongated shaft comprises articulationof the elongated shaft, and wherein the compression compensationparameter relates an angle of articulation of the elongated shaft to anaxial length of compression of the elongated shaft.
 3. The roboticsystem of claim 2, wherein the angle of articulation comprises acommanded angle of articulation.
 4. The robotic system of claim 2,wherein the angle of articulation comprises a measured angle ofarticulation.
 5. The robotic system of claim 4, further comprising atleast one electromagnetic (EM) sensor positioned on the elongated shaft,wherein the measured angle of articulation is determined based on asignal from the EM sensor.
 6. The robotic system of claim 1, wherein thecompression compensation parameter relates a pull wire displacement toan axial length of compression of the elongated shaft.
 7. The roboticsystem of claim 1, wherein the drive input comprises a linear driveinput, and wherein the compression compensation parameter relates alinear displacement of a portion of the linear drive input to an axiallength of compression of the elongated shaft.
 8. The robotic system ofclaim 1, wherein the non-transitory computer readable medium comprises aradio frequency identification (RFID) tag.
 9. The robotic system ofclaim 8, wherein the RFID tag is positioned at the instrument base. 10.The robotic system of claim 9, wherein the RFID tag is configured tocommunicate the compression compensation parameter when activated by aRFID reader of the robotic arm.
 11. The robotic system of claim 1,wherein the elongated shaft comprises a sheath having a channel formedtherethrough, the channel extending along an axis of the sheath.
 12. Therobotic system of claim 1, further comprising one or more additionalpull wires.
 13. The robotic system of claim 1, wherein thenon-transitory computer readable medium is remotely located from theinstrument base and the elongated shaft.
 14. The robotic system of claim1, wherein the non-transitory computer readable medium is positioned onor within the elongated shaft.
 15. The robotic system of claim 1,wherein the compression compensation parameter is a non-linear function.16. The robotic system of claim 1, wherein the compression compensationparameter is used to calculate axial compression of the elongated shaftfor a given movement measurement of the pull wire.
 17. A robotic system,comprising: a robotic arm; and a medical instrument, comprising: anelongated shaft extending between a distal portion and a proximalportion; an instrument base connected to the proximal portion of theelongated shaft, the instrument base including a drive input configuredto be driven by a corresponding drive output of the robotic arm; anon-transitory computer readable medium storing a compressioncompensation parameter that relates movement of the elongated shaft toaxial compression of the elongated shaft; and a pull wire connected tothe distal portion of the elongated shaft and the drive input; whereinthe robotic arm is configured to move along a virtual rail to advance orretract the instrument base based at least in part on the storedcompression compensation parameter, and wherein the robotic arm moves toadvance or retract the instrument base at substantially the same time asthe drive input actuates the pull wire to cause movement of theelongated shaft.
 18. The robotic system of claim 17, wherein movement ofthe elongated shaft comprises articulation of the elongated shaft, andwherein the compression compensation parameter relates an angle ofarticulation of the elongated shaft to an axial length of compression ofthe elongated shaft.
 19. The robotic system of claim 18, wherein theangle of articulation comprises one of a commanded angle of articulationand a measured angle of articulation.
 20. The robotic system of claim17, wherein the compression compensation parameter relates a pull wiredisplacement to an axial length of compression of the elongated shaft.21. The robotic system of claim 17, wherein the non-transitory computerreadable medium comprises a radio frequency identification (RFID) tag.22. The robotic system of claim 21, wherein the RFID tag is positionedat the instrument base.
 23. The robotic system of claim 22, wherein theRFID tag is configured to communicate the compression compensationparameter when activated by a RFID reader of the robotic arm.
 24. Therobotic system of claim 17, wherein the elongated shaft comprises asheath having a channel formed therethrough, the channel extending alongan axis of the sheath.
 25. A medical instrument, comprising: anelongated shaft extending between a distal portion and a proximalportion, the elongated shaft configured for insertion, in use, into alumen of a patient; an instrument base connected to the proximal portionof the elongated shaft, the instrument base including an attachmentinterface configured to facilitate attachment to a robotic arm; a lineardrive input positioned at the instrument base; a non-transitory computerreadable medium storing a compression compensation parameter thatrelates a linear displacement of a portion of the linear drive input toan axial length of compression of the elongated shaft; and a pull wireconnected to the distal portion of the elongated shaft, the pull wireextending along the elongated shaft between the distal portion and thelinear drive input, the linear drive input configured to actuate thepull wire to cause movement of the elongated shaft based at least inpart on the stored compression compensation parameter.
 26. The medicalinstrument of claim 25, wherein movement of the elongated shaftcomprises articulation of the elongated shaft, and wherein thecompression compensation parameter relates an angle of articulation ofthe elongated shaft to an axial length of compression of the elongatedshaft.
 27. The medical instrument of claim 25, wherein the compressioncompensation parameter relates a pull wire displacement to an axiallength of compression of the elongated shaft.